Brett Aqualine 275-3290-00
Hi Limit Switch, Bulb Type, Sunne 20 amp

Single pole rated at 25 amps with temperature rating set at 121°F. Best results are obtained when the bulb is installed in a dry well or groove tube at or immediately before the heater 12" capillary length, 5/16" bulb thickness This is a safety device! If it is found to be out of calibration, do not attempt to perform a field adjustment! Replace bad hi limit with a new one